Marks brother is five older than mark their combined ages add up to 23 how ild is mark

Since Mark's brother is five years older than Mark and their combined ages add up to 23 than Mark must be 9.

Since 9 + 14 = 23, and 14 - 9 = 23 
Mark brother is 14 but Mark is 9

Mark is 9 years old.
Hope this helps :0

152

Step-by-step explanation:

The average change of the function on the interval x=a=4 and x=b=6 is equal to the slope of the secant line  joining (a, f(a)) and (b,f(b)).

#Substitute for the x values in the function:

The slope of the interval is calculated as:

Hence, the avergae rate of change of the function is 152